Why does my computer run slow, but only on certain websites?

It is not the website it could be your flash player is not working properly. You can download updates from the flash player website which will tell you your operating system and you can update. It could also be your java which needs updating go to java. com and see if there are updates for your system.

some sites are heavy loaded with graphics and flash software's which require your cache memory to be used very abruptly so try changing the cache memory size of your computer as it is sometimes full and requires first deleting and then storing of temporary files of the internet websites, another factor can be ram try increasing will also work

On certain websites your computer may run slower not because of your internet connection or computer, but because of site traffic. If the site has a lot of viewers and people on the site it will start to run slower if the server cannot accomodate all the viewers. Some webiste like Youtube have servers that can handle many viewers.

If websites are slowing you down take into consideration what site your on. If its a popular site with many members such as Facebook, Myspace, Cardomain and site like it it could be bogged down by the web sites users. Try logging in at a time when most people wouldn't be on.